Vibrio splendidus O-antigen structure: a trade-off between virulence to oysters and resistance to grazers

A major debate in evolutionary biology is whether virulence is maintained as an adaptive trait and/or evolves to non-virulence. In the environment, virulence traits of non-obligatory parasites are subjected to diverse selective pressures and trade-offs. Here, we focus on a population of Vibrio splendidus that displays moderate virulence for oysters. A MARTX (Multifunctional-autoprocessing repeats-in-toxin) and a type-six secretion system (T6SS) were found to be necessary for virulence toward oysters, while a region (wbe) involved in O-antigen synthesis is necessary for resistance to predation against amoebae. Gene inactivation within the wbe region had major consequences on the O-antigen structure, conferring lower immunogenicity, competitive advantage and increased virulence in oyster experimental infections. Therefore, O-antigen structures that favour resistance to environmental predators result in an increased activation of the oyster immune system and a reduced virulence in that host. These trade-offs likely contribute to maintaining O-antigen diversity in the marine environment by favouring genomic plasticity of the wbe region. The results of this study indicate an evolution of V. splendidus towards moderate virulence as a compromise between fitness in the oyster as a host, and resistance to its predators in the environment.     

Designed miR-19a/b sponge induces apoptosis in lung cancer cells through the PI3K-PTEN-Akt pathway regulation

Molecular Biology Reports - MicroRNAs (miRNAs) are one of the main factors in cancer development and can alter the activity of proto-oncogenic or tumor suppressor genes. The miR-17-92 cluster,...     

The gut microbiota profile in psoriasis: a Brazilian case-control study

The pathogenesis of psoriasis, an immune-mediated chronic inflammatory skin disease, remains unclear. Studies have shown an association between psoriasis and intestinal inflammation; in this context, the influence of the gut microbiota on the immune response of psoriasis has become a focus of recent research. The present research evaluated the composition and diversity of the gut microbiota of 21 participants with psoriasis from a Brazilian referral dermatology service compared to 24 healthy controls. A stool sample was collected from each participant at the time of inclusion in the study, and the samples were analysed by sequencing the 16S rRNA gene. The recruitment of research participants involved matching between groups by sex, age, body mass index, comorbidities and smoking and the exclusion of several criteria that could potentially influence the gut microbiota and the interpretation of the data. There was an increase in the Dialister genus and Prevotella copri species in patients with psoriasis compared to the control group. A reduction in the Ruminococcus, Lachnospira and Blautia genera, as well as in the Akkermansia muciniphila species, was also verified in the psoriasis group compared to the control group. Furthermore, patients with psoriasis exhibited less gut microbiota diversity than controls.     

Physical fitness in community‐dwelling older adults is linked to dietary intake,gut microbiota,and metabolomic signatures

When humans age, changes in body composition arise along with lifestyle‐associated disorders influencing fitness and physical decline. Here we provide a comprehensive view of dietary intake, physical activity, gut microbiota (GM), and host metabolome in relation to physical fitness of 207 community‐dwelling subjects aged +65 years. Stratification on anthropometric/body composition/physical performance measurements (ABPm) variables identified two phenotypes (high/low‐fitness) clearly linked to dietary intake, physical activity, GM, and host metabolome patterns. Strikingly, despite a higher energy intake high‐fitness subjects were characterized by leaner bodies and lower fasting proinsulin‐C‐peptide/blood glucose levels in a mechanism likely driven by higher dietary fiber intake, physical activity and increased abundance of Bifidobacteriales and Clostridiales species in GM and associated metabolites (i.e., enterolactone). These factors explained 50.1% of the individual variation in physical fitness. We propose that targeting dietary strategies for modulation of GM and host metabolome interactions may allow establishing therapeutic approaches to delay and possibly revert comorbidities of aging.     

Cultivation of the microalga <Emphasis Type="Italic">Neochloris oleoabundans</Emphasis> for biofuels production and other industrial applications (a review)

Microalgae cultivation for biofuels production and other applications has gained considerable interest recently. Despite their simple structures, microalgae can accumulate significant amounts of neutral lipids per dry cell weight compared to other energy crops. Neochloris oleoabundans is a promising microalga known for its high lipid content and biomass growth rate compared to other species cultivated for biofuels synthesis; therefore, it is considered as a suitable candidate for biodiesel synthesis. This review paper covers several key aspects associated with the cultivation and applications of the microalga N. oleoabundans. Biomass composition, factors affecting the growth, and biomass and lipid productivities of this species were addressed. In addition, different growth conditions as well as alternative readily available nutrient media to support the growth of N. oleoabundans were presented in this review.     

Death attributed to ventricular arrhythmia induced by thioridazine in combination with a single Contac C capsule.

Phenothiazines are known to produce electrocardiographic repolarization abnormalities. Thioridazine and mesoridazine appear to induce such changes more frequently than other neuroleptics and are also known to induce fatal ventricular arrhythmia. The woman described in this article died after taking her usual dose of thioridazine, 100 mg/d, in combination with a single capsule of Contac. C, a decongestant-antihistamine containing phenylpropanolamine and chlorpheniramine. Phenylpropanolamine, an ephedrine-like drug, was thought to have favoured the initiation by thioridazine of the ventricular arrhythmia that led to the woman''s death. It is therefore suggested that ephedrine-like medications not be given to patients receiving thioridazine.